Eine Kern- -Strahlung bei der leichten Elementen [A nuclear -radiation in the light elements] in Die Naturwissenschaften 18 p. 705, 1930

Berlin: Springer, 1930. 1st Edition. FIRST EDITION IN ORIGINAL WRAPS OF BOTHE & BECKER'S INFLUENTIAL 1930 ANNOUNCEMENT & DESCRIPTION OF THE PRODUCTION OF NEUTRAL PENETRATING RADIATION; while not the gamma radiation they believed it to be, within two years their work would lead directly to Chadwick's discovery of the neutron.

Walther Bothe and Herbert Becker believed they had observed gamma radiation -- -rays (very energetic photons) being emitted from a beryllium target bombarded by -particles; in reality they had seen neutrons. By 1932, James Chadwick had correctly interpreted Bothe and Becker's research and discovered the neutron. Bothe won the Nobel Prize in Physics in 1954 for his work on the wave-particle duality of radiation, but the prize committee also specifically mentioned the work offered here.

Note that later in this same year, 1930, Bothe and Becker published a fuller discussion of their findings in Zeitschrift für Physik 66, 1930. We offer that work separately.

Chadwick's seminal discovery was built directly on two other sets of experiments, each unimaginable without the next. The first was the work of Bothe and Becker offered here."In 1927, Bothe began to study the transformation of light weight elements by bombardment of the nucleus with alpha particles... In 1930, after moving to the University of Giessen, Bothe and assistant H. Becker made a startling and perplexing new discovery while investigating such reactions. They observed for the first time the emission of an entirely new form of high energy radiation that was even more penetrating than the hardest known gamma rays" (Nobel Prize Committee).

The second came in 1931 when Irène and Frédéric Joliot-Curie performed experiments using the radiation Bothe and Becker found and demonstrated that when it touched paraffin or any other hydrogen-containing compound, it ejected protons with very high energy from that substance. Still, they couldn't replicate Bothe and Becker's work and they too "fell short of a satisfactory explanation of the phenomenon" (ibid).

Upon hearing of the Curie's experiments, James Chadwick "immediately understood that the ejections reported by the Curies required energy too high to have been produced by gamma rays. [He believed] and argued that the reaction must be caused by a new massive particle" (History of Physics: The Wenner Collection).

Chadwick designed an experimental test confirming the Curie's results, but then went further. After accurately measuring the energy of the ejected nuclei, Chadwick saw that the "ultra penetrating radiation" could not be a gamma ray but had to be composed of particle of mass 1 and of electric charge 0: this, then, had to be the neutron. Chadwick won the 1935 Nobel Prize for his discovery, but even at that time, the prize committee acknowledge the centrality of Bothe and Becker's research to Chadwick's accomplishment. CONDITION & DETAILS: Complete issue. Original wraps. 4to. Provenance: Bearing the ownership signature of Christian Füchtbauer (1877-1959), a German experimental physicist & professor who published in AdP & ZfP. No institutional markings. Bright & clean. Fine condition.